SYSTEMIC TOXICITY AND FIELD EFFICACY OF IMIDACLOPRID, PYMETROZINE, AND TRIAZAMATE AGAINST MYZUS-PERSICAE (HOMOPTERA, APHIDIDAE) ON SPINACH

Spinach, Spinacia oleracea, L., plants infested with green peach aphid s, Myzus persicae (Sulzer), were used in laboratory and field studies to determine the systemic activity and field efficacy of three recentl y developed aphicides. Outer leaves of laboratory test plants were tre ated with various rates of the compounds. Aphid mortality was recorded for treated outer leaves and nontreated inner leaves to determine tra nslaminar and systemic efficacies, respectively. Concentrations equiva lent to suggested rates of triazamate, through systemic movement in th e plant, were sufficient to control greater than or equal to 90% of ap hids on nontreated leaves. Imidacloprid also produced a level of aphid control through systemic activity; however, the suggested rate was no t as effective against aphids on nontreated leaves as that of triazama te. Mortality from pymetrozine was erratic on both treated and nontrea ted plant parts. In the held study, imidacloprid and a high rate of tr iazamate were more effective than other treatments. A low rate of tria zamate typically was not different from pymetrozine. All aphicide trea tments included in the field study resulted in fewer aphids than in no ntreated control plots.